Dental attachment



Oct. 9, 1928. 1,686,950

w. G. BRIDGE DENTAL ATTACHMENT Filed Jan. 1927 Patented Oct. 9, 1928.

UNITED STA WALTER e. BRIDGE,

OF NEWTON, MASSACHUSETTS, ASSIGNOR TO CHARLES E. PARK- H'URST, OF SOMERVILLE, MASSACHUSETTS.

DENTAL ATTACHMENT.

Application filed January 5, 1927. Serial No. 159,106.

This invention relates to an improved type of dental attachments for securing partial dentures to the natural teeth.

It has become generally recognized among prosthesians that it is desirable'to support thermore, it is advantageous to provide atmitting use of reasonable tolerances and vatachments of this character so that they may be applied to the natural and artificial dentures without necessity for extremely accu-- rate workmanship or paralleling, thus perriations in behavior of the employed materials. Not only is it preferable tosallow the abutmentteeth to retain their normal degree of-mobility in order to maintain the mucosa in a healthy condition, but it is also desirable to have the artificial denture bear partially at least upon the gunrin order moderately to compress the same, especially during mandibular movement,'thus aiding natural circulation and venous blood flow and keeping the gums in a normal healthy condition. Especially when the abutment teeth are inclined at an angle, it is desirable to avoid rigid attachment of the artificial dentures thereto, since occlusion will tend to set up excessive strains which are likely tocause ultimate loss of natural teeth. Use of adaptable securing means or attachments between natural and artificial dentures, on the other hand, permits the latter to be somewhat selflocating or self-adjustingin relation to the gum and to the, opposing teeth upon which they bear during occlusion.

The present invention provides dental attachments of a character which permits the artificial dentures to have limited mobility in relation to the abutment teeth and to the gum. these attachments being convenient to apply both to the natural and to the artificial more, these attachments are comparatively sturdy and capable of enduring considerable rough usage or abuse and per-nut ready re moval or replacement of the artificial denture, and, in general, provide distinct advantages over attachments of this character which have previously been in use in the hands of dentists or prosthesians.

The above and further objects and advantageous-features attributable to the invention will be'apparent to those skilled in the art upon a reading of the subjoined description and claims in conjunction with the accompanying drawings, in which:

Fig. 1 is a side elevational view of a form exemplifying an installation of the inven t-ion; I

Fig. 2 is a central, vertical section through the same; r r p v Fig. 3 is a bottom elevation ofthe upper part of such a form; t

attachments, which more particularly form the subject matter of this invention;

Fi 45 is a section on line 5-5 of Fig. 4; Fig. 6 is an enlarged side elevation of the attachment; and I 7 is a section on line 7-7 of Fig. 6. Referring to the accompanying drawings and. more particularly to Fig. 3 thereof, it will be seen that the improved form of attachments disclosed herein comprises tongue and groove members adapted to secure each end of the artificial dentureto the adjoining anchorage or abutment tooth. In general, either the tongue or thegroove element may be secured to the artificial denture and the complementary'element may be secured to the natural tooth.

Preferably the groove member is in the form of an elongate element 1 having an out er curved surface of regular form and being provided with a flat surface Qadjoining the tongue member, the intermediate part of this surface being cut away to provide the dovetail groove 3. The tongue member l preferably comprises a flat plate 5 from one side of which the dovetail tongue 6 projects (Fig. 7). Themembers are preferably so proportionedand dimensioned that'the tongue fits loosely within the groove in order to permit a limited relative movementin all directions. Adjoining either enchthe depth of tongue is reduced, to provide additionalclearanc designated by the numeral 7, Fig. 5, in order to allowa rocking or oscillatory movement between the tongue and groove members to a greater. extent than melamine in ether lUz direct-ions, except in a cirection in longitudinal alignment with the tongue and groove.

A detachable retaining pin 10 normally holds the tongue and groove members 1 and 1 against excessive endwise movement. Preferably the retaining pin comprises a cylindrical body portion 11 (Fig. 7) with a threaded shank 12 adjoining a slotted head 13. r threadedto receive shank 1.2 of pin 10, while theopposite portion oi the groove member has an aligned depression or opening 1 1 to receive the cylindrical end of the pin, so that location of the pin in the groove member and starting oi the threads is facilitated. v

In order to permit a limited vertical move ment or movement in longitudinal relation to the tongue and groove, the outer edge of the former is provided with an oblong slot 16 which looselyengages the mid portion of the cylindrical body portion of pin 11 and permits the pin together with the element 1 to have a limited longitudinal movement in re .lation to member 4.

Figs. 1, 2 and3 disclose a typical application of the invention, wherein the above-described attachments are used to secure a partial denture to the natural abutment teeth, .the' former being designated by numeral 25' and the latter being designated by numerals 2G, and 27 respectively. The artificial denture in such an insulation is preferably so located that it will have a limited bearing at all times upon the underlying gum and so that upon occlusion the gum will be somewhat compressed therebeneath, although this action will be limited by the size and po sition of the slots 16 and the pins 10; Similarly movement transversely and in alignment with the ridge will be permitted, as well as a limited rockingor oscillatory movement. It is to be understood that attachments of the character described above will be provided for the use of the individual practitioner and that one of the elements, e. g. the

tongue element, may be located upon a recessed portion of the inlay or coping which has been applied to the abutment tooth, being temporarily held in place thereon by dental wax, and that thereafter it may be invested with suitable plaster, the wax being removed by. the ordinary gas flame or the like, and the investment serving to hold the attachment in place while it is soldered upon the inlay or coping.

If desired, the recess in the coping maybe omitted, and a ground surface may be provided upon the same, wax being used temporarily to hold the attachment upon this surface and use oi? the investment solder following as described above. The attachment members having been located upon the abut ment or anchorage teeth, the artificial denturewill then be fitted with the complementary portions of the attachments arranged in One side of the groove element 1 is,

proper position to hold the denture in its de- After completion of the artisired location. ficial denturewith the attachments, e. g. the groove elements, thus located thereon, the denture may be located in the mouth by securing the complementary portions of the attachments to each other by inserting and tightening the pins 10.

It is evident that the fitting of artificial dentin-es which are held'in place byjatta'chments of this character does not require extreme mechanical accuracy and that the shape of the tongue maybe readily changed in order to permitgreater freedom of movement in any desired direction and also that slot 16 may beenlarged in order to permit greater vertical movement or further compression of the gum by the denture, the latter being especially desirable after resorption has occurred. Obviously, the denture is readily removable for replacement, cleaning, or the like, bythe removal of pins or'screws 10 and it may be easily secured upon the abutment teeth, since the form of the pins 10 permits the ready ficial denture to compress, stimulate, and.

massagethe underlying gum to a satisfactory degree and are adapted to be readilyreformed in order to permit further bearing upon the gum when necessary or desirable.

I claim: 7

1. A dental attachment comprising elements adapted to secure an artificial denture to an abutmenttooth, said elements comprising loosely interfitting dovetailed tongueand groove portions, and a pin adapted to be threaded. into the grooved element and en gaging an oblong slot in the tongue element, said pin having a head and a threaded shank adjoining the same, the remainder of the pin being free from threading. V V

2. A' dental attachment comprising elements adapted to'secure an artificial denture to an abutment tooth, said elements including loosely fitting dovetailed tongue and groove portions, and a pin fixed in the grooveelement and engaging a slot in the tongue element, said pin having a slotted head and extending from one side of the groove to the other, and being adapted to be threaded into the side oi the grooveelementnext to its head, the remainder of the pin being free from threads. Y

8. A dental attachment comprising elements adapted to secure an artificial denture to an abutment tooth, said elements includ ing a loosely fitting dovetail tongue and groove, a removable pin in one of the elements, having a threaded portion screwed into said element and having a portion free from threads engaging a slot in the other element, said tongue and groove being shaped a to have a greater clearance at their ends than at their mid-portions, said slot having its greater dimension in a direction substantially corresponding to the longitudinal extent of the tongue and groove.

i. A dental attachment comprising elements adapted to secure an artificial denture to an abutment tooth, said elements including loosely fitting dovetailed tongue and groove portions, and a pin fixed in the groove element and having one side of its intermediate portion engaging an elongate notch in the edge-of the tongue element and having the opposite side of the intermediate portion,

engaging anotch in said grooved element, said pin having a slotted head and extending from one side ofthe groove to the other, and being adapted to be threaded into the side of the groove element next to its head, the remainder 

